Layer Cake

OpenLayers is a JavaScript library that allows you to integrate maps into web pages. You can program the geodetic data directly or read it from a database.

OpenStreetMap is a free project that was founded in 2004 with the goal of creating a freely usable and expandable world map. Contributors gather geodata, load the information into the database, and edit the data. The data includes roads, railways, buildings, and other geographic information. The data from Open-StreetMap finds its way into highway maps, as well as cycling maps, walking maps, and countless special applications.

The geospatial information in OpenStreetMap is freely available, so people can integrate the maps into their own blogs or websites. Even the raw data is freely accessible for development work, including integration with route-finding tools and mobile navigation apps. For instance, you can use OpenStreet-Map to display points of interest (POIs), tourist trails, or weather stations (Figure 1). You can also use OpenStreetMap for accessing and displaying land registration data. The only tribute you need to pay to the community is an indication of the source with a reference to Open-StreetMap.

Graphic artists often face the problem of turning a photograph into an image that will tile over a larger surface. This task is not as easy as it sounds, but if you’re up for the challenge, this tutorial will give you a first-hand look at some advanced tools in the GIMP toolkit.